Mapping and layout: Best GPS unit?

I've seen a lot of good information and discussions in this section of the forums, but one thing I've not seen is a discussion about mapping and layout GPS units. Let me be clear. I'm not talking about something that will ever be used on a bike. I don't really care about that for the purposes of this discussion. Here's what matters to me in the current frame of discussion:

Custom Maps: I want to be able to take a map of a proposed trail location/layout, load it in the GPS, go to the property, and navigate the proposed trail. A lot of GPS units do this.

Track Retention: I want a unit that creates accurate tracks that are easily loaded onto <insert your favorite mapping software> to make maps of existing trails.

Hi-Res Topo option: This should be self explanatory. I'd consider Garmin's 24K topo maps the standard minimum. I'm willing to purchase the maps, or whatever, but I'm interested in knowing what everyone thinks is the best.

Obviously, accuracy and precision are critical. Is a GLONASS enabled system always going to be able to provide better results, or does looking for GLONASS just limit options?

Also, there's a huge disparity in screen sizes. Usually the price varies in proportion to the screen size. For those of you who have large screen units, is it worth it? Do you like it? If you skipped the larger screen because of money, have you regretted that choice?

Have I missed anything? I turn the floor over to you folks. Discuss. Thanks.

You're going to have to give some limits to frame the discussion. I could send you to a $10,000 Trimble with ArcPad and you'll be spending a pile of dough to get absolutely everything on your list.

The software on your computer to manipulate the data is honestly more important than the handheld you use.

GLONASS is just another constellation of satellites out there. There are others. Compass, Beidou, Galileo, etc. The ability to access more of those satellites to fix a location (and the capability to lock on as many as are visible) can give you a more accurate position. GLONASS by itself, however, is actually less accurate than GPS. Signal fix is a little quicker. But in marginal situations where you might not have enough GPS satellites visible in the sky, being able to pick up on one or two GLONASS birds can make the difference between no fix and a reasonably close position fix. The more you spend, the more of those you can access.

Frankly, 24k topos are going to be the best you can get unless you make your own from LIDAR elevation data. But you reach a point of diminishing returns. Put too much detail on your maps and you can't make out one feature from the next. 24k is probably the most detailed you should consider using.

I am honestly not sure what you're talking about regarding Track Retention. Do you want to be able to edit an already existing track (or at least add onto it) in the device while you're out in the field? For that, you need a survey grade receiver running a real mapping program like ArcPad. If you just want to piece bits of a track together on your computer at home, then like I said before, the software on your computer is more important than the hardware.

For trail work, I'd consider a Garmin GPSMap 60CSx or 70CSx to be a minimum. The newer etrex models would probably be sufficient, but with those you have a smaller antenna which partially negates the ability to access additional satellites. Also, with the 60, 76, 62, and 78 series models, you can attach an external antenna to put on your hat or backpack to improve reception. Not an option with an etrex. I have an Oregon 450 that works reasonably well. It is bigger, so I expect a larger antenna than the etrex...but I don't know for sure about that. I have noticed on some projects that certain locations the track is not exact. But neither is anyone else's track for the same spot. In tough spots, you need to switch data collection techniques and lay down some averaged waypoints.

Nate, that's a start, thanks. I suppose I should point out that I'm aware of multi-point survey GPS units, but obviously consider them out of my price range.

I understand GLONASS is simply another array of sats. - my questions relate to units such as the new eTrex and the impending Oregon 600 that are able to use GPS and GLONASS simultaneously, in conjunction with WAAS. It's sort of one of those "more has to be better" things, right? Except that I'm also aware that on it's own GLONASS isn't as accurate as GPS. Which is why I was wondering if GLONASS unit's are "worth it".

Yeah, I get the map density thing. My point there, I think, was if you recommend a unit that isn't a Garmin, it should have that sort of map data available. Sometimes I'm not the easiest person to follow, off the cuff....

As far as track retention, I think maybe we get back to one of your previous comments regarding the software on my computer being more important than the unit itself. I have an eTrex that's one generation too old to use custom maps. I've used it for some mapping work, but it seems to want to vomit all of the tracks that exist on it on to the maps I'm working on when I work on a map, and not really give me away to select what track or tracks I'm actually interested in seeing. Again, I suspect it's a software limitation, but it seems like I was using Basecamp. I could be wrong about that. But since it's Garmin's "default" software for that sort of thing....I should point out that it looks like basecamp has been upgraded several times since the version I was using. I'll see if that makes any difference, at some point.

So, to be fair, I was looking at the eTrex 30 as a GLONASS capable unit. If GLONASS isn't all it's cracked up to be, then I assume the GPSMap 62 series would be the same (newer) as the 60 you refer to? The Oregon 450 was on my list of units to look at if for non-GLONASS as well, largely because many times I've wished the screen on my eTrex was larger.

Unfortunately, the only two hand held GPS units I have any experience with are both eTrex units, one was the original Legend, which would lose signal in heavy cloud cover, and the replacement for that, the Legend HCx, which in my opinion, also has an issue with the visibility of the "color" parts of its display in bright sunlight. Beyond that, there's my phone, which the other day I had out just for kicks as I was walking a property, doing land nav with a topo map to scout for potential POI's or areas we'd need to avoid when putting trails there, and noticed that on more than one occasion my phone showed my location to be several hundred feet from where I actually was - and in case you're wondering, there was only one creek on the property, and I know I was on the south side of it while the phone showed me on the north side of the creek. So, yes, I'm certain it was the phone and not me - clearly whatever I end up with has to be more accurate than that.

Again, thanks for your input thus far Nate, it sounds like (and looks from your signature/blog) you know a fair amount about GPS, and that's good. Because I'm looking for people with practical experience to give advice on this. Honestly, none of these units are "cheap" to me, so I want to get the right one the first time out.

For basic mapping needs, the Garmin 62S (or the older 60CS, which is just slower) is more than enough. I loaded mine with 1:20 topo + orthophoto of the area where I'm working, and sometime with extra custom maps (cadastre, hand-drawn map by the locals, etc).

If you really need more accuracy, external antenna helps but averaged tracked processed at home is usually enough. You're running a trail in a forest after all.

A Trimble unit in the wood is totally overkill in my opinion. For a bike park where every inch of elevation is important, that's something else...

If you really need more accuracy, external antenna helps but averaged tracked processed at home is usually enough. You're running a trail in a forest after all.

Ok. I've seen GPS units that average waypoint locations. I pretty much understand that. I've seen a lot of this "averaged track processed at home" stuff though, and don't really know anything about it. Anyone got a link to a procedure for this? This is the sort of thing that, if I understand correctly, makes maps more consistent by allowing 5 or so passes to be combined into an average of the 5 tracks, but I have no idea how this would be done. Special software? Thanks again for the feedback and pointers on this.

I have been using Backwoods Navigator Pro gps app in my 7" Galaxy Tab for the last year. I find it superior to the dedicated gps I was using in the past, I especially like the large map display. I usually use it in airplane mode because there is no cell coverage. You can download the ARC GIS topo maps to the memory card for free, and I like them because they show private property boundaries. Unless your track will become a legal description of a trail ROW really you don't need surveyor level accuracy for user maps. For route scouting purposes the big display wins hands down.

I don't think GLONASS is a player in the CONUS. The US GPS system has implemented WAAS, and most of the current Garmin handhelds can seem to produce 3m accuracy pretty reliably when WAAS signal is present.

That said, I have used several handhelds on water, on trails (hiking and riding) and in flight. I have also used CF cards GPS plugins, smartphones and tablets. My best performer to date is a Garmin 62ST.

I have an Etrex I used to death. It finally had a battery corrode in it and the tab broke off. RIP little Etrex.

I have an Oregon that works well, but the touch screen seems to chew through batteries pretty quick.

The 62ST I have using been most of the time now has good battery life, and excellent sensativitey. This is really what sets it apart. The 62 seems to get a lock quicker and hold it in the trees much better than other units. I think this is what is most important. You need to be able to lock the most satelites and maintain a WAAS signal to hold the 3m accuracy.

I do not really have much opinion on the screens. I honestly do not use the mapping much on the screen. I do flag waypoints and shoot bearings, but the on screen mapping is not a big deal for me. All my mapping is done in post processing once I get home (from saved tracks).

Ok. I've seen GPS units that average waypoint locations. I pretty much understand that. I've seen a lot of this "averaged track processed at home" stuff though, and don't really know anything about it. Anyone got a link to a procedure for this? This is the sort of thing that, if I understand correctly, makes maps more consistent by allowing 5 or so passes to be combined into an average of the 5 tracks, but I have no idea how this would be done. Special software? Thanks again for the feedback and pointers on this.

For basic track processing, I use Touratech QV5 Pro. It's cheaper than ARC GIS and easier to use than other full-blown GIS software, like Quantum GIS. Touratech can merge/average many saved tracks in a single track which will be much closer to reality. I found that a 3 pass give a pretty good result.

Even when the GPS unit claim 3m accuracy, it can be off by quite a bit. Averaging many passes alleviate that issue a bit.

Mapping and layout: Best GPS unit?

Topofusion does track averaging also but it has trouble in really dense twisty networks because it can be difficult to distinguish an intersection from an inaccurate track segment.

I typically overlay multiple tracks and averaged waypoints and then hand draw the "averaged" trail.

I bought an Oregon primarily because of text entry. When scouting I put descriptive names on my waypoints and sometimes comments. Typing with the rocker button of the GPSmap models or the joystick of the etrex models drives me nuts. 5 button presses for one letter? Ugh.

If typing is a priority, look at a touchscreen model.

Bsieb mentioned something else...the smartphone or tablet. With this, the software is going to be the primary limitation. I would personally pair the device with an external bluetooth gps receiver to get an accuracy boost.

The advantage here is the screen for that imagery. I don't use it for much but trail work is one thing I use it for. The newer garmins can load imagery but the screens do not have resolutions high enough imo to REALLY be able to use it. It is a tricky balance between features and making a device that will run for a couple of days on two AA batteries.

Where I live, a more sensitive piece of electronics would need to be protected from water. We do a lot of trail scouting in the rain. It is manageable but needs to be addressed. Where you live will have its own issues. Dust? Lots of rocks (drop risk)?

I do not know what software is out there for tablets and mapping to be able to compare. But some things I think are important:
1. Waypoint averaging. I don't ever take a waypoint without averaging it nowadays.

2. Ability to edit a waypoint name and description. I need to know why I marked a waypoint to begin with.

3. The ability to stop a track, save it, and start a new one.

4. The ability to load data from previously in .gpx or .shp formats so I can see the existing trail network. Bonus points for shapefile compatibility and the ability to load multiple files (so I can also load property boundaries and other data of interest). Boundaries in the old topo maps are usually incorrect these days.

One nice benefit of taking that kind of hardware out is that you have a geotagging camera to identify and record maintenance needs or control features or simply mark trail features. Some of the garmins have a camera but it adds substantial weight to the handheld. To the point that, imo, it becomes uncomfortable to hold for long.

when I can be sure that the above feature list can be met with a small cheap tablet with an affordable app, I might give it a shot. It at least needs to do what my existing handheld can do, preferably more to leverage that screen real estate and processing power without being unnecessarily encumbered by overreliance on "the cloud".

I would love if trimble made an app that allowed any tablet to function as a survey grade receiver in one important way. Primarily by saving ALL of the raw gps data from the receiver in the specific format (.ssf IIRC) so it could be post-processed with ground station differential corrections.

I hear that GLONASS compatibility does benefit receivers. It speeds up the amount of time to satellite lock. And it gives improved accuracy in situations where few satellites are visible.

However do not confuse WAAS in this discussion. WAAS is more or less part of GPS and consists of two satellites providing differential corrections. AFAIK, GLONASS does not have a comparable feature but Europe is building out the Galileo satellite constellation that will operate similarly. Europe currently uses EGNOS, which is a ground-based system.

^NateHawk- I left my last Garmin on the roof of my truck and was faced with replacing it. I had just got a refurbed ($180) 7" Galaxy Tab and bought the BCN app for $10 to get me by and I never looked back. I can easily hold the tablet in one hand and in a day the battery level barely moves if I turn the screen off when not viewing it. I can put the microSD card in my computer to transfer or just connect by bluetooth or usb. In the real world I need a gps track that is useful to the FS or a NEPA Survey contractor, or a rec bicyclist or map maker. The tablet gives me that and I don't need to carry a paper topo for reference.

I bought an Oregon primarily because of text entry. When scouting I put descriptive names on my waypoints and sometimes comments. Typing with the rocker button of the GPSmap models or the joystick of the etrex models drives me nuts. 5 button presses for one letter? Ugh.

If typing is a priority, look at a touchscreen model.

This answers a huge question for me. I've never liked trying to name waypoints on my eTrex units. I actually started carrying a pad of paper and a pen to write down the default numbers and translate that to a usable note. This is a very big plus on the side of the Oregon units.

I hear that GLONASS compatibility does benefit receivers. It speeds up the amount of time to satellite lock. And it gives improved accuracy in situations where few satellites are visible.

However do not confuse WAAS in this discussion. WAAS is more or less part of GPS and consists of two satellites providing differential corrections. AFAIK, GLONASS does not have a comparable feature but Europe is building out the Galileo satellite constellation that will operate similarly. Europe currently uses EGNOS, which is a ground-based system.

Yeah, I understand the difference between GLONASS and WAAS - one is another set of sats run by the Russians, the other is a differential land based system. That link you posted does a pretty good job of explaining both and where GLONASS might be helpful - a background in communications doesn't hurt when reading it though.

^NateHawk- I left my last Garmin on the roof of my truck and was faced with replacing it. I had just got a refurbed ($180) 7" Galaxy Tab and bought the BCN app for $10 to get me by and I never looked back. I can easily hold the tablet in one hand and in a day the battery level barely moves if I turn the screen off when not viewing it. I can put the microSD card in my computer to transfer or just connect by bluetooth or usb. In the real world I need a gps track that is useful to the FS or a NEPA Survey contractor, or a rec bicyclist or map maker. The tablet gives me that and I don't need to carry a paper topo for reference.

I see BCN is one of the apps that lets you download maps so you're not reliant on the crappy "caching" of maps or an internet connection. I'm assuming for map data downloads, you are pretty much limited to what the app developers make available, and that you cannot give the app a source for a different web service for a tiled dataset that's not preloaded? For example, in Topofusion or any quality GIS you can provide the details of a WMS (web mapping service) and the program will load it. With my Oregon, even though image quality is lacking (it is reduced for memory/processing efficiency), I can load up any WMS in Topofusion and send it to the handheld as a custom map.

Okay, nevermind. More digging and I see that the app can do this. One thing that's not terribly clear is how much map data it can handle. The developer says don't load a whole state...how much do you use?

Poking around the app's website, it seems the developer posts tracks and waypoints for some hiking trails. I see these files are in a proprietary format. Does the app allow you to load tracks and waypoints from a more universal format, like .gpx, .kml, or .shp? Proprietary file formats are a PITA when the point is data sharing. Fortunately, Garmin's not been too difficult about allowing developers access to its .img basemap format so there are converters. But this app is not nearly as mature and the format is new to me. Can I easily make my own .bcn trail/waypoint overlays with data I have already?

I see some discussion about offering trail overlays as a paid add-on, but that's not what I want. This is currently what I see as a big hang-up for most apps. Difficulty using overlays. Garmin's not great at it, but at least it's possible with some know-how. And it's currently my biggest hangup to going the route you've gone, bsieb.

^NateHawk- I'm not a technical enough user to answer many of those questions. For $10, come on, it works well for me, and I haven't bought anything extra. I also have downloaded the color aerials for the Zuni Mts, handy sometimes. Not sure what the limit is on download size but Android devices have card slots so where there's a will there's a way. Much easier than hacking maps into older garmins. Plus I can post pics to fb and mtbr on the go with the tablet.

For basic track processing, I use Touratech QV5 Pro. It's cheaper than ARC GIS and easier to use than other full-blown GIS software, like Quantum GIS. Touratech can merge/average many saved tracks in a single track which will be much closer to reality. I found that a 3 pass give a pretty good result.

Even when the GPS unit claim 3m accuracy, it can be off by quite a bit. Averaging many passes alleviate that issue a bit.

Looking at the Touratech website, it appears that track merging/averaging is a feature only available on the Pro software package, is that correct?

If so, are there other alternatives (TopoFusion)? I could really use this feature, but I don't want to go to hand-drawing. It might look sketchy to my land manager if I'm hand drawing trails.

Mapping and layout: Best GPS unit?

My hand drawn trails look as good or better than raw gps tracks. I posted a map in this forum a few weeks ago and all the trails were hand drawn. Land manager was almost beside himself with the map.

And yeah, Topofusion has an averaging function. It is the Network tool, because it also simplifies things and places intersections where it appears there is one. There are some settings to fiddle with to make it more or less sensitive to intersections and loops and whatnot that you can adjust for the trail system you are working with.

My hand drawn trails look as good or better than raw gps tracks. I posted a map in this forum a few weeks ago and all the trails were hand drawn. Land manager was almost beside himself with the map.

And yeah, Topofusion has an averaging function. It is the Network tool, because it also simplifies things and places intersections where it appears there is one. There are some settings to fiddle with to make it more or less sensitive to intersections and loops and whatnot that you can adjust for the trail system you are working with.

Thanks Nate,

I am required to submit shapefiles in support of my proposed trails. The problem I run into is that the tracks I walk off sometimes look wonky. Things like trail segments that are actually separated by 20-30 yards (yes, it's that tight in a few, isolated places) cross over each other. Or they appear on the wrong side of the park boundary. Or cross over ski trails.

We've been shut down for 2 years waiting for the DNR to fix their master development plan. We have to get an audit by a protected plant species professional. I don't want to give them any additional excuses to drag their feet. Good GPS data might make the difference in getting approval in 1 or 2 tries vs multiple back-and-forth.

Mapping and layout: Best GPS unit?

The trails i have mapped have occasionally been only a few feet apart separated by only some downed timber. Hand drawing was the only realistic way to do it.

In tough spots I recommend setting waypoints and averaging them using the gps's averaging function. Then you play connect the dots and interpolate the curves of the trail from memory or your raw track.

We use drawn maps for all of our proposals. We then load the proposal maps into a GPS that supports custom maps and lay out something very similar to our proposal, allowing for anomalies we find on the ground. The trick is having a GPS that does all of the above and is accurate enough to keep you inside of setbacks and boundaries. The results from scouting the new property I'm working with the other day showed clearly that my phone, regardless of how good the software is, wasn't capable of that level of accuracy.

I've been using a combination:
* Koordinates - the one place for geodata - a great place to get vectors of boundaries, features and 5m contours.
* Garmin Oregon (GPX files and ability to follow tracks drawn in Google Earth after conversion from KMZs). Geotagged photos of constraints are really useful to prompt memory without typing in the field.
* Adobe Illustrator (handles vectors, photos from Google Earth, arial photos etc).

When I first started working for my company, our GPS units were sub-meter and WAAS enabled. When I got into dense tree cover (hemlocks are the worst) or just in an awkward area, sometimes I lost all satellite coverage. At the time, it paid to carry a compass for backup.

Last year I was introduced to GLONASS. Our new GPS units can lock onto as many as 20+ satellites in the open and 10+ even in dense cover. Plus we were able to lose the backpack with an external antenna and just carry the hand-held unit.

If you can get a GPS with GLONASS, go for it. I think more consumer units will begin making this standard. You won't necessarily increase the accurateness of your data, but you will lock onto more satellites, more often.

Since this thread is about a year old, I'm hoping to resurrect it and see if in the year-ish since the last update there's been any change to the GPS recommendations. I've been digging around trying to find a nice multi-GNSS receiver and while I came across the Alberding A07 it seems to be made of unobtanium.

From this and a few other threads I'm also looking at the Garmin Oregon series. I regularly map SE Michigan MTB trails that tend to be tight and twisty, then do my maps via a GNSS -> OpenStreetMap -> Adobe Illustrator workflow that's done great for me. But, in order to do this I need a quality receiver. I've been using my phone (Nexus 4 or 5 with MyTracks) to gather data to date, but I'd really prefer something a bit more rugged...

That Alberding looks to be on par with Trimble and other professional grade receivers. Unobtanium is about right. USED equipment on ebay will still cost in excess of $5,000 easy. Certainly better than what most folks use, but at what cost?

If I was buying something for trail layout right now, I like the Garmin Monterra. It has some features of professional receivers, with a more reasonable price point. It runs Android, does GPS+GLONASS, is wifi, bluetooth, NFC, and ANT+, and some additional features.

That Alberding looks to be on par with Trimble and other professional grade receivers. Unobtanium is about right. USED equipment on ebay will still cost in excess of $5,000 easy. Certainly better than what most folks use, but at what cost?

If I was buying something for trail layout right now, I like the Garmin Monterra. It has some features of professional receivers, with a more reasonable price point. It runs Android, does GPS+GLONASS, is wifi, bluetooth, NFC, and ANT+, and some additional features.

Do you think the lack of protruding antenna would decrease sensitivity a bit? While I don't have much tree cover to deal with this time of the year, as it warms up much of what I want to map will soon be heavily treed.

I also can't help but feel that being an Android device it's just a bit overcomplicated...

It's too bad there's no easy way to compare it to my Nexus 5 to see if it's really that much better. (Without doing the two side by side...)

It runs android and gives you some app flexibility but Garmin has its own app interface, too.

Where this thing is better than other Garmins is that you can use programs that are more powerful than standard gps os stuff. Mobile gis. I used mobile gis in grad school, undergrad, and at a couple of jobs in between. You can manipulate the data you collect in the field and so much more.